Let .
Compute AB and BA and hence deduce that matrix multiplication is, in general, not commutative.

Question

Let  . ​
Compute AB and BA and hence deduce that matrix multiplication is, in general, not commutative.
​

Quizplus · Accepted Answer

AB = 11eab448_e871_abc2_acdb_31456c2ef4ed_TB6027_11 × 11eab448_e871_d2d6_acdb_d19f06caebb4_TB6027_11
= 11eab448_e871_abc2_acdb_31456c2ef4ed_d2d6acdb31456c2ef4ed_TB6027_11
BA = 11eab448_e871_d2d6_acdb_d19f06caebb4_TB6027_11 × 11eab448_e871_abc2_acdb_31456c2ef4ed_TB6027_11
= 11eab448_e871_d2d6_acdb_31456c2ef4ed_abc2acdb_TB6027_11
Since AB ≠ BA, matrix multiplication is not commutative, so only option D is correct.

Let . ​

Let .